Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/31/2004
Publication Date: 1/1/2004
Citation: Bourassa, D.V., Fletcher, D.L., Buhr, R.J., Berrang, M.E., Cason Jr, J.A. 2004. Recovery of Salmonellae from Trisodium Phosphate-Treated Commercially Processed Broiler Carcasses After Chilling and After Seven-Day Storage. Poultry Science. 83(12):2079-2082.
Interpretive Summary: Salmonellae are common causative bacterial agents of human food poisoning associated with raw chicken carcasses. Rinsing carcasses with trisodium phosphate (TSP) is an antibacterial intervention step used in commercial processing plants, before carcass chilling, to reduce the recovery of salmonellae and other bacteria. The effects of TSP on salmonellae recovery on the day of processing and after refrigeration of the carcasses for one week (to simulate retail sales conditions) has not been reported simulating commercial conditions. In the first two trials carcasses were chilled in two separate small scale chillers, one for the control and one for the TSP-treated carcasses. In the subsequent trials, each carcass was placed into a plastic bag (with ice and water) and then chilled. For the first two trials, on the day of processing control carcasses were 85% salmonella positive compared to 45% positive for TSP-treated carcasses, and after refrigeration for seven days 75% of the control carcasses were positive compared to 35% for the TSP-treated carcasses. These high recovery rates for salmonellae suggested cross contamination during chilling. For the subsequent trials that used chilling in individual bags, control carcasses were 46% salmonellae positive compared to 26% for the TSP-treated carcasses on the day of processing. After seven days of refrigeration salmonellae recovery was reduced for both the control carcasses (20% positive) and the TSP-treated carcasses (4% positive). TSP treatment depressed the level of recovery of salmonellae from raw broiler carcasses on the day of processing and after seven day of refrigeration. Refrigeration of carcasses for seven days, in the absence of TSP-treatment, also reduced the level of salmonellae recovery.
Technical Abstract: Experiments were conducted to determine the effect of pre-chill trisodium phosphate (TSP) treatment on reducing salmonellae recovery from broiler carcasses immediately after chilling or following 7 d of storage. Carcass were sampled for salmonellae using whole carcass enrichment for 24 h at 37 C. In each of seven trials, 40 carcasses were obtained pre-chill from a commercial processing plant. Batches of four carcasses were either subjected to a 5 s dip in 10% TSP (Treatment) or not dipped (Control). For trials 1 and 2, TSP treatment and control groups were chilled in separate chill tanks for 45 min. For trials 3 through 7, carcasses were individually bagged with ice and water prior to chilling. Half the carcasses in each treatment group were sampled immediately after chilling (Day 0) and half after 7 d. For trials 1 and 2, 85% of control carcasses were salmonellae positive on Day 0 compared to 45% of the TSP-treated carcasses, and after 7 d, 75% of control carcasses were positive compared to 35% for the TSP-treated carcasses. For trials 3 through 7, 46% of control carcasses were salmonellae positive on Day 0 compared to 26% of the TSP-treated carcasses, and after 7 d, 20% of control carcasses were positive compared to 4% of the TSP-treated carcasses. TSP treatment also resulted in significantly higher pH values for rinses.